Mirrlees Blackstone Limited was formed on 1 June 1969 by the merger of Mirrlees National Limited (formerly Mirrlees, Bickerton and Day) and Blackstone & Company Limited. All were, at the time, members of the Hawker Siddeley Group.[6]

Mirrlees Blackstone were bought by MAN Diesel, along with the diesel businesses of the collapsed GEC, although little remains. The Stockport factory has been partly demolished and replaced with a new office and warehouse facility which still serves the aftermarket for spares and servicing of Lister Blackstone engines under the MAN Diesel & Turbo tagline. The Blackstone name lives on with the Blackstones F.C..

A British Rail Class 10 diesel locomotive, fitted with a Blackstone diesel engine.

Blackstone supplied a number of diesel engines for British Rail locomotives but these were largely unsuccessful and were not adopted.

In the 1980s, four of the well-established Paxman Valenta-engined HST trainset power cars were re-engined with Mirrlees Blackstone MB190 engines for trials. These were unsuccessful and Valenta engines were reinstalled. Eventually, in the 2000s, the fleet was re-engined with MTU V16 4000 engines.

The Class 10 was a small number (150 vs 900) of the widespread Class 08 0-6-0 diesel-electric shunter, in which a Blackstone ER6T engine was fitted instead an English Electric 6KT. They were withdrawn early.

The projected Type 3 freight Class 38 of the 1980s was considered for use of a Mirrlees MB275T. Four of the refurbished Class 37/9 at this period were rebuilt with the engine as a trial, two more used the Ruston RK270T as a comparison. In the end, the Class 38 was cancelled in favour of the Class 60.

Class 60 heavy freight Type 5 locomotives of the 1980s replaced the projected Class 38. Like the 38, these used the Mirrlees MB275T engine. (Contract of 109 MB275 engines received by Mirrlees). These 8 cylinder engines, compared to the more common V12 or V16 engines in this power range, were hoped to show lower operating costs owing to their simplicity.

Examples of Blackstone engines can be seen at the Anson Engine Museum near Manchester. The former Stamford Museum in Stamford, Lincolnshire, also had a Blackstone engine on display, and held an archive relating to the company.